few times I was added to such groups, and every time I press "leave and report spam" button/
i think this is best behaviour in such cases, also I hope that telegram support bans such channels
Correct because it's inappropriate to add us without our consent and it's so annoying to see those unwanted channel popped up if we do something important, Hit spam and leave is the proper way to do for that matters so that there channel will be banned by telegram and those owners will learn there lesson about spam adding.
It's frustrating especially if telegram notification is activated that it keep buzzing just for a reason you'd been added without you even trying to join. Bounty spreadsheet s should hide or not required telegram usernames in their form to avoid these scenes scammer uses it to as if act that they're project have many followers. We should revenge by hitting spam,or even by messaging in their group that "how come I'm here" for them to be aware that their scheme is no longer working or convincing.